From 2d0a21e70e78bbb4ec79657dc594e0c16c3eacb3 Mon Sep 17 00:00:00 2001 From: wanggeng <450292408@qq.com> Date: Sun, 4 Sep 2022 15:13:02 +0800 Subject: [PATCH] =?UTF-8?q?=E5=A2=9E=E5=8A=A0Rsa=E5=8A=A0=E5=AF=86?= =?UTF-8?q?=E6=96=B9=E6=B3=95?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../java/ink/wgink/util/security/RsaUtil.java | 207 ++++++++++++++++++ 1 file changed, 207 insertions(+) create mode 100644 basic-util/src/main/java/ink/wgink/util/security/RsaUtil.java diff --git a/basic-util/src/main/java/ink/wgink/util/security/RsaUtil.java b/basic-util/src/main/java/ink/wgink/util/security/RsaUtil.java new file mode 100644 index 00000000..4bf54dd0 --- /dev/null +++ b/basic-util/src/main/java/ink/wgink/util/security/RsaUtil.java @@ -0,0 +1,207 @@ +package ink.wgink.util.security; + +import org.springframework.util.Base64Utils; + +import javax.crypto.BadPaddingException; +import javax.crypto.Cipher; +import javax.crypto.IllegalBlockSizeException; +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.nio.charset.StandardCharsets; +import java.security.*; +import java.security.interfaces.RSAKey; +import java.security.interfaces.RSAPrivateKey; +import java.security.interfaces.RSAPublicKey; +import java.security.spec.PKCS8EncodedKeySpec; +import java.security.spec.X509EncodedKeySpec; + +/** + * @ClassName: RsaUtil + * @Description: Rsa工具 + * @Author: wanggeng + * @Date: 2022/9/2 15:00 + * @Version: 1.0 + */ +public class RsaUtil { + + private static final String RSA_ALGORITHM = "RSA"; + + /** + * 公钥加密 + **/ + public static byte[] encryptWithPublicKey(final byte[] data, RSAPublicKey publicKey) { + return doRSA(publicKey, Cipher.ENCRYPT_MODE, data); + } + + /** + * 公钥解密 + **/ + public static byte[] decryptByPublicKey(final byte[] data, RSAPublicKey publicKey) { + return doRSA(publicKey, Cipher.DECRYPT_MODE, data); + } + + /** + * 私钥加密 + **/ + public static byte[] encryptWithPrivateKey(byte[] data, RSAPrivateKey privateKey) { + return doRSA(privateKey, Cipher.ENCRYPT_MODE, data); + } + + /** + * 私钥解密 + **/ + public static byte[] decryptWithPrivateKey(byte[] data, RSAPrivateKey privateKey) { + return doRSA(privateKey, Cipher.DECRYPT_MODE, data); + } + + + private static byte[] doRSA(RSAKey key, int mode, byte[] data) { + try { + Cipher cipher = Cipher.getInstance(RSA_ALGORITHM); + cipher.init(mode, (Key) key); + return doRSA(cipher, mode, data, key.getModulus().bitLength()); + } catch (Exception e) { + throw new IllegalArgumentException(e); + } + } + + private static byte[] doRSA(Cipher cipher, int mode, byte[] data, int keySize) throws IOException, BadPaddingException, IllegalBlockSizeException { + int maxBlock; + if (mode == Cipher.DECRYPT_MODE) { + maxBlock = keySize / 8; + } else { + maxBlock = keySize / 8 - 11; + } + int length = data.length; + ByteArrayOutputStream baos = new ByteArrayOutputStream(); + try { + int offset = 0; + byte[] buf; + int i = 0; + // 对数据分段加密 + while (length - offset > 0) { + if (length - offset > maxBlock) { + buf = cipher.doFinal(data, offset, maxBlock); + } else { + buf = cipher.doFinal(data, offset, length - offset); + } + baos.write(buf, 0, buf.length); + i++; + offset = i * maxBlock; + } + baos.flush(); + return baos.toByteArray(); + } finally { + baos.close(); + } + } + + /** + * 创建公钥 + * + * @param publicKey + * @return + */ + public static RSAPublicKey generatePublicKey(String publicKey) { + try { + KeyFactory keyFactory = KeyFactory.getInstance(RSA_ALGORITHM); + X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(Base64Utils.decodeFromString(publicKey)); + return (RSAPublicKey) keyFactory.generatePublic(x509KeySpec); + } catch (Exception e) { + throw new IllegalArgumentException("generate publicKey caught error", e); + } + } + + /** + * 创建私钥 + * + * @param privateKey + * @return + */ + public static RSAPrivateKey generatePrivateKey(String privateKey) { + try { + KeyFactory keyFactory = KeyFactory.getInstance(RSA_ALGORITHM); + PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(Base64Utils.decodeFromString(privateKey)); + return (RSAPrivateKey) keyFactory.generatePrivate(pkcs8KeySpec); + } catch (Exception e) { + throw new IllegalArgumentException("generate privateKey caught error", e); + } + } + + /** + * 获取公钥字符串 + * + * @param publicKey + * @return + */ + public static String getPublicKeyString(PublicKey publicKey) { + return Base64Utils.encodeToString(publicKey.getEncoded()); + } + + /** + * 获取私钥字符串 + * + * @param privateKey + * @return + */ + public static String getPrivateKeyString(PrivateKey privateKey) { + return Base64Utils.encodeToString(privateKey.getEncoded()); + } + + /** + * 生成公私钥对 + * + * @return + * @throws NoSuchAlgorithmException + */ + public static KeyPair generateKeyPair(int keySize) throws NoSuchAlgorithmException { + KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(RSA_ALGORITHM); + keyPairGenerator.initialize(keySize); + return keyPairGenerator.genKeyPair(); + } + + public static void main(String[] args) throws NoSuchAlgorithmException { + KeyPair keyPair = RsaUtil.generateKeyPair(512); + PublicKey pubKey = keyPair.getPublic(); + PrivateKey priKey = keyPair.getPrivate(); + + String publicKey = RsaUtil.getPublicKeyString(pubKey); + String privateKey = RsaUtil.getPrivateKeyString(priKey); + + System.out.println("公钥：" + publicKey); + System.out.println("私钥：" + privateKey); + + System.out.println(); + + String content = "站在大明门前守卫的禁卫军，事先没有接到有关的命令。hello world!"; + byte[] data = content.getBytes(StandardCharsets.UTF_8); + + System.out.println("明文：" + content); + System.out.println("明文大小：" + data.length); + + //公钥加密 + byte[] encodeBuf = RsaUtil.encryptWithPublicKey(data, RsaUtil.generatePublicKey(publicKey)); + System.out.println("密文：" + Base64Utils.encodeToString(encodeBuf)); + System.out.println("密文大小：" + encodeBuf.length); + + //私钥解密 + byte[] decodeBuf = RsaUtil.decryptWithPrivateKey(encodeBuf, RsaUtil.generatePrivateKey(privateKey)); + System.out.println("解密后文字：" + new String(decodeBuf, StandardCharsets.UTF_8)); + + // 私钥加密 + System.out.println(); + + String content2 = "我是中国人"; + byte[] data2 = content2.getBytes(StandardCharsets.UTF_8); + System.out.println("明文：" + content2); + // 私钥加密 + byte[] privateEncodeBuf = RsaUtil.encryptWithPrivateKey(data2, RsaUtil.generatePrivateKey(privateKey)); + System.out.println("密文：" + Base64Utils.encodeToString(privateEncodeBuf)); + System.out.println("密文大小：" + privateEncodeBuf.length); + // 公钥解密 + byte[] publicDecodeBuf = RsaUtil.decryptByPublicKey(privateEncodeBuf, RsaUtil.generatePublicKey(publicKey)); + System.out.println("解密后文字：" + new String(publicDecodeBuf, StandardCharsets.UTF_8)); + + } + +}